The Bureau of Indian Affairs has once again upheld its reputation as the epitome of government waste and mismanagement.

The Department of Interior and the administration's Office of Management and Budget last week disclosed the unhappy results of a BIA financial audit: $95 million of the agency's $1.3 billion 1990 budget have been misspent or erroneously recorded.Investigators found 12,000 employees could access the BIA's accounting system and easily alter records. In 1990 alone more than 500,000 accounting adjustments were made. They also found ledger accounts couldn't be balanced because the agency didn't use standard double entry accounting methods. Furthermore, the BIA exhibited poor control over its $500 million in annual procurement and grant contracts.

And investigators don't believe the audit means financial mismanagement took place just last year. It's gone on for decades.

The audit results are the latest in a string of disturbing disclosures the past two years about gross mismanagement within the BIA, which has overseen the nation's Indian reservations and welfare of native Americans for 167 years.

Audit results came at a bad time, following the agency's first budget increase in 10 years and a few months before hearings on its 1992 budget. The BIA says it desperately needs funding because the population it serves is growing. Interior Secretary Manuel Lujan is lobbying White House budget officials for an additional $100 million for Indian educational programs.

Congress is justified in feeling a bit slighted after the audit findings. It boosted the BIA's budget based on commitments from the agency that it would clean up its act. The BIA says the audit is part of the cleanup process, and Lujan says a plan is in place to overhaul the agency's accounting system by October.

But Congress should be certain changes are in place or at least under way before appropriating any more tax money to an agency with the BIA's appalling record for mishandling money.