<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information extracted fromt he
Montgomery Street Income Securities, Inc. Semi-annual Report for the period
ended 6/30/2000 and is qualified in its entirety by reference to such financial
statements.
</LEGEND>
<CIK> 0000067813
<NAME> MONTGOMERY STREET INCOME SECURITIES, INC.
<SERIES>
<NUMBER> 010
<NAME> MONTGOMERY STREET INCOME SECURITIES, INC.
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 230,870
<INVESTMENTS-AT-VALUE> 225,785
<RECEIVABLES> 3,894
<ASSETS-OTHER> 1
<OTHER-ITEMS-ASSETS> 65
<TOTAL-ASSETS> 229,745
<PAYABLE-FOR-SECURITIES> 38,920
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 215
<TOTAL-LIABILITIES> 39,135
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 200,818
<SHARES-COMMON-STOCK> 10,276
<SHARES-COMMON-PRIOR> 10,290
<ACCUMULATED-NII-CURRENT> 3,573
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (8,696)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (5,085)
<NET-ASSETS> 190,610
<DIVIDEND-INCOME> 114
<INTEREST-INCOME> 7,522
<OTHER-INCOME> 0
<EXPENSES-NET> 659
<NET-INVESTMENT-INCOME> 6,977
<REALIZED-GAINS-CURRENT> (5,249)
<APPREC-INCREASE-CURRENT> 3,467
<NET-CHANGE-FROM-OPS> 5,195
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (3,391)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 0
<NUMBER-OF-SHARES-REDEEMED> (29)
<SHARES-REINVESTED> 15
<NET-CHANGE-IN-ASSETS> 1,590
<ACCUMULATED-NII-PRIOR> (14)
<ACCUMULATED-GAINS-PRIOR> (3,446)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 461
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 659
<AVERAGE-NET-ASSETS> 188,982
<PER-SHARE-NAV-BEGIN> 18.37
<PER-SHARE-NII> 0.68
<PER-SHARE-GAIN-APPREC> (.17)
<PER-SHARE-DIVIDEND> (.33)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 18.55
<EXPENSE-RATIO> 0.70
</TABLE>
