Payment Date: 04/25/00
------------------------------------------------------------
BA MORTGAGE SECURITIES, INC.
Mortgage Pass-Through Certificates, Series 1998-4
BANK OF AMERICA, FSB, MASTER SERVICER
------------------------------------------------------------
<TABLE>
<CAPTION>
Class Information Current Payment Information
----------------------------------------------------------------------------------------------------------------------------------
Beginning Pass Thru Principal Interest Total Principal Interest
Type Class Code Name Cert. Bal. Rate Dist. Amt. Dist. Amt. Dist. Losses Shortfalls
----------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C>
Senior IA-1 13,783,962.31 6.650000% 376,015.91 76,386.12 452,402.03 0.00 0.00
IA-2 20,595,625.09 6.250000% 747,331.62 107,268.88 854,600.50 0.00 0.00
IA-3 6,800,000.00 6.650000% 0.00 37,683.33 37,683.33 0.00 0.00
IA-4 23,800,000.00 6.600000% 0.00 130,900.00 130,900.00 0.00 0.00
IA-5 45,152,417.55 6.500000% 822,534.80 244,575.60 1,067,110.40 0.00 0.00
IA-6 4,031,750.10 6.750000% 0.00 22,678.59 22,678.59 0.00 0.00
IA-7 62,210,382.82 6.628750% 248,589.20 343,647.56 592,236.77 0.00 0.00
IA-8 11,981,258.91 7.119930% 47,876.44 71,088.10 118,964.54 0.00 0.00
IA-9 4,147,358.85 7.500000% 16,572.61 25,920.99 42,493.61 0.00 0.00
IA-10 0.00 6.750000% 0.00 0.00 0.00 0.00 0.00
IA-11 3,356,158.66 6.750000% 0.00 0.00 0.00 0.00 0.00
IA-12 59,500,000.00 6.750000% 0.00 334,687.50 334,687.50 0.00 0.00
IIA-1 25,329,152.83 6.500000% 591,509.69 137,199.58 728,709.27 0.00 0.00
IIA-2 25,828,000.00 6.500000% 0.00 139,901.67 139,901.67 0.00 0.00
IIA-3 19,183,152.57 6.500000% 0.00 103,908.74 103,908.74 0.00 0.00
IIA-4 0.00 6.500000% 0.00 0.00 0.00 0.00 0.00
IIA-5 0.00 6.500000% 0.00 0.00 0.00 0.00 0.00
IIA-6 24,213,876.15 6.500000% 96,960.76 131,158.50 228,119.25 0.00 0.00
I-X-1 0.00 0.245697% 0.00 0.00 0.00 0.00 0.00
I-X-2 104,348,042.01 0.245697% 0.00 21,365.02 21,365.02 0.00 0.00
I-X-3 70,972,000.00 0.245697% 0.00 14,531.35 14,531.35 0.00 0.00
I-X-4 73,610,722.13 0.245697% 0.00 15,071.62 15,071.62 0.00 0.00
II-X 848,969.97 6.500000% 0.00 4,598.59 4,598.59 0.00 0.00
I-PO 100,496.63 0.000000% 125.12 0.00 125.12 0.00 0.00
II-PO 240,897.96 0.000000% 1,028.42 0.00 1,028.42 0.00 0.00
Residual R-I 0.00 6.750000% 0.00 0.00 0.00 0.00 0.00
R-II 0.00 6.500000% 0.00 0.00 0.00 0.00 0.00
R-III 0.00 6.750000% 0.00 0.00 0.00 0.00 0.00
----------------------------------------------------------------------------------------------------------------------------------
Subordinate IM 6,785,675.51 6.750000% 6,341.77 38,169.42 44,511.20 0.00 0.00
IB-1 3,117,556.80 6.750000% 2,913.61 17,536.26 20,449.87 0.00 0.00
IB-2 1,650,702.58 6.750000% 1,542.72 9,285.20 10,827.92 0.00 0.00
IB-3 1,283,989.02 6.750000% 1,199.99 7,222.44 8,422.43 0.00 0.00
IB-4 917,275.46 6.750000% 857.27 5,159.67 6,016.94 0.00 0.00
IB-5 917,272.52 6.750000% 857.27 5,159.66 6,016.92 0.00 0.00
IIM 1,149,227.81 6.500000% 4,601.91 6,224.98 10,826.89 0.00 0.00
IIB-1 422,811.53 6.500000% 1,693.08 2,290.23 3,983.31 0.00 0.00
IIB-2 302,673.45 6.500000% 1,212.01 1,639.48 2,851.49 0.00 0.00
IIB-3 362,276.84 6.500000% 1,450.68 1,962.33 3,413.02 0.00 0.00
IIB-4 181,604.07 6.500000% 727.21 983.69 1,710.89 0.00 0.00
IIB-5 302,570.36 6.500000% 1,211.60 1,638.92 2,850.52 0.00 0.00
----------------------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------------------
Totals - - 363,616,376.27 - 2,973,153.70 2,059,844.04 5,032,997.75 - -
----------------------------------------------------------------------------------------------------------------------------------
Class Information
--------------------------------------------------------------------------------
Ending Cert. Unpaid
Type Class Code Name Notional Bal. Interest
--------------------------------------------------------------------------------
Senior IA-1 13,407,946.40 0.00
IA-2 19,848,293.47 0.00
IA-3 6,800,000.00 0.00
IA-4 23,800,000.00 0.00
IA-5 44,329,882.75 0.00
IA-6 3,940,357.34 0.00
IA-7 61,961,793.61 0.00
IA-8 11,933,382.47 0.00
IA-9 4,130,786.24 0.00
IA-10 0.00 0.00
IA-11 3,375,037.05 0.00
IA-12 59,500,000.00 0.00
IIA-1 24,737,643.14 0.00
IIA-2 25,828,000.00 0.00
IIA-3 19,183,152.57 0.00
IIA-4 0.00 0.00
IIA-5 0.00 0.00
IIA-6 24,116,915.39 0.00
I-X-1 0.00 0.00
I-X-2 102,534,403.33 0.00
I-X-3 70,972,000.00 0.00
I-X-4 73,192,498.91 0.00
II-X 832,073.63 0.00
I-PO 100,371.51 0.00
II-PO 239,869.53 0.00
Residual R-I 0.00 0.00
R-II 0.00 0.00
R-III 0.00 0.00
--------------------------------------------------------------------------------
Subordinate IM 6,779,333.73 0.00
IB-1 3,114,643.19 0.00
IB-2 1,649,159.86 0.00
IB-3 1,282,789.02 0.00
IB-4 916,418.19 0.00
IB-5 916,415.25 0.00
IIM 1,144,625.90 0.00
IIB-1 421,118.44 0.00
IIB-2 301,461.44 0.00
IIB-3 360,826.16 0.00
IIB-4 180,876.87 0.00
IIB-5 301,358.77 0.00
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Totals - - 360,662,100.96 -
--------------------------------------------------------------------------------
</TABLE>
<PAGE>
Payment Date: 04/25/00
------------------------------------------------------------
BA MORTGAGE SECURITIES, INC.
Mortgage Pass-Through Certificates, Series 1998-4
BANK OF AMERICA, FSB, MASTER SERVICER
------------------------------------------------------------
<TABLE>
<CAPTION>
Class Information Current Payment Information
Factors per $1,000
------------------------------------------------------------------------------------------------------------------------
Beginning Pass Thru CUSIP Principal Interest Ending Cert./
Type Class Code Name Cert. Bal.(Face) Rate Numbers Dist. Dist. Notional Bal.
------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
------------------------------------------------------------------------------------------------------------------------
Senior IA-1 13,783,962.31 6.650000% 055240GY5 23.500994 4.774133 837.996650
IA-2 20,595,625.09 6.250000% 055240GZ2 29.893265 4.290755 793.931739
IA-3 6,800,000.00 6.650000% 055240HA6 0.000000 5.541667 1,000.000000
IA-4 23,800,000.00 6.600000% 055240HB4 0.000000 5.500000 1,000.000000
IA-5 45,152,417.55 6.500000% 055240HC2 16.450696 4.891512 886.597655
IA-6 4,031,750.10 6.750000% 055240HD0 0.000000 4.962092 862.152811
IA-7 62,210,382.82 6.628750% 055240HE8 1.892499 2.616174 471.712486
IA-8 11,981,258.91 7.119930% 055240HF5 1.892499 2.810029 471.712486
IA-9 4,147,358.85 7.500000% 055240HG3 1.892499 2.960031 471.712486
IA-10 0.00 6.750000% 055240HH1 0.000000 0.000000 0.000000
IA-11 3,356,158.66 6.750000% 055240HJ7 0.000000 0.000000 1,125.012350
IA-12 59,500,000.00 6.750000% 055240HK4 0.000000 5.625000 1,000.000000
IIA-1 25,329,152.83 6.500000% 055240HL2 21.907766 5.081466 916.209005
IIA-2 25,828,000.00 6.500000% 055240HM0 0.000000 5.416667 1,000.000000
IIA-3 19,183,152.57 6.500000% 055240HN8 0.000000 2.244249 414.322950
IIA-4 0.00 6.500000% 055240HP3 0.000000 0.000000 0.000000
IIA-5 0.00 6.500000% 055240HQ1 0.000000 0.000000 0.000000
IIA-6 24,213,876.15 6.500000% 055240HR9 3.729260 5.044558 927.573669
I-X-1 0.00 0.245697% 055240HS7 0.000000 0.000000 0.000000
I-X-2 104,348,042.01 0.245697% 055240HT5 0.000000 0.186862 896.781445
I-X-3 70,972,000.00 0.245697% 055240HU2 0.000000 0.204748 1,000.000000
I-X-4 73,610,722.13 0.245697% 055240HV0 0.000000 0.094339 458.138103
II-X 848,969.97 6.500000% 055240HW8 0.000000 3.429642 620.563312
I-PO 100,496.63 0.000000% 055240HX6 1.215729 0.000000 975.276066
II-PO 240,897.96 0.000000% 055240HY4 3.528522 0.000000 822.992979
Residual R-I 0.00 6.750000% 055240JF3 0.000000 0.000000 0.000000
R-II 0.00 6.500000% 055240JG1 0.000000 0.000000 0.000000
R-III 0.00 6.750000% 055240JH9 0.000000 0.000000 0.000000
------------------------------------------------------------------------------------------------------------------------
Subordinate IM 6,785,675.51 6.750000% 055240HZ1 0.918831 5.530198 982.227432
IB-1 3,117,556.80 6.750000% 055240JA4 0.918831 5.530198 982.227432
IB-2 1,650,702.58 6.750000% 055240JB2 0.918831 5.530198 982.227435
IB-3 1,283,989.02 6.750000% 055240JJ5 0.918831 5.530198 982.227429
IB-4 917,275.46 6.750000% 055240JK2 0.918831 5.530198 982.227429
IB-5 917,272.52 6.750000% 055240JL0 0.918831 5.530198 982.227435
IIM 1,149,227.81 6.500000% 055240JC0 3.729260 5.044558 927.573665
IIB-1 422,811.53 6.500000% 055240JD8 3.729260 5.044557 927.573662
IIB-2 302,673.45 6.500000% 055240JE6 3.729260 5.044557 927.573658
IIB-3 362,276.84 6.500000% 055240JM8 3.729260 5.044558 927.573677
IIB-4 181,604.07 6.500000% 055240JN6 3.729260 5.044558 927.573667
IIB-5 302,570.36 6.500000% 055240JP1 3.729263 5.044562 927.574545
------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
Totals - - 363,616,376.27 - - - - -
------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>
------------------------------------------------------------
BA MORTGAGE SECURITIES, INC.
Mortgage Pass-Through Certificates, Series 1998-4
BANK OF AMERICA, FSB, MASTER SERVICER
------------------------------------------------------------
--------------------------------------------------------------------------------
COLLATERAL INFORMATION
--------------------------------------------------------------------------------
Total
-----
Prin balance 263,846,253.53 96,815,848.04 360,662,101.57
Loan count 825 292 1117
Avg loan rate 7.427134% 7.025463% 7.32
Prepay amount 2,005,180.57 309,885.77 2,315,066.34
--------------------------------------------------------------------------------
FEES AND ADVANCES
--------------------------------------------------------------------------------
Total
-----
Master serv fees 94,461.68 38,705.05 133,166.73
Sub servicer fees 0.00 0.00 0.00
Trustee fees 997.88 365.69 1,363.56
Agg advances N/A N/A N/A
Adv this period 0.00 0.00 0.00
--------------------------------------------------------------------------------
LOSSES & INSURANCE COVERAGES
--------------------------------------------------------------------------------
Total
-----
Realized losses 0.00 0.00 0.00
Cumulative losses 0.00 0.00 0.00
Coverage Amounts Total
---------------- -----
Bankruptcy 0.00 0.00 0.00
Fraud 3,730,870.14 1,298,233.99 5,029,104.13
Special Hazard 3,072,105.95 1,743,066.36 4,815,172.31
Aggregate Certificate Information
-----------------------------------------------------------------------------
Class Aggregate Aggregate Aggregate
Type Percentage Prepay Pct. End Cert. Bal.
-----------------------------------------------------------------------------
Senior 95.222932% 100.000000% 346,222,740.33
-----------------------------------------------------------------------------
Junior 4.777068% 0.000000% 17,369,026.82
-----------------------------------------------------------------------------
--------------------------------------------------------------------------------
DELINQUENCY INFORMATION
--------------------------------------------------------------------------------
Period Loan Count Ending Stated Balance
------ ---------- ---------------------
30 to 59 days 0 0.00
60 to 89 days 0 0.00
90 or more 0 0.00
Foreclosure 0 0.00
Totals: 0 0.00
--------------------------------------------------------------------------------
<PAGE>
--------------------------------------------------------------------------------
REO INFORMATION
--------------------------------------------------------------------------------
REO Date Loan Number Ending Stated Balance Book Value
-------- ----------- --------------------- ----------
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
N/A # 0 N/A
Totals: 0 N/A
Current Total Outstanding Balance: 0.00
Current Total Outstanding Number of Loans: 0
<PAGE>
--------------------------------------------------------------------------------
OTHER INFORMATION
--------------------------------------------------------------------------------
Amount/Withdrawal Total/Ending Bal.
----------------- -----------------
Available remittance amount 5,032,997.75 5,032,997.75
Principal remittance amount 2,973,153.70 2,973,153.70
Interest remittance amount 2,059,844.04 2,059,844.04
