Remember all those rumors and hot inside stories about unusual proposals that might be in President Reagan's fiscal 1989 budget?

Lots of those "proposals," it turns out, are falling by the wayside.

In one story, it was said that the White House might suggest "privatizing" the government's National Institutes of Health, the world's leading biomedical research institution.

Other stories said the president might propose removing the $8,400-a-year earnings limit for Social Security beneficiaries aged 65 to 69 (there is no limit above 69) and sharply increase Medicare fees to elderly people, while cutting Medicaid payments to states.

According to still others, Social Security was going to revamp the letters it sends to people who are not retired but who inquire whether the giant pension system has properly recorded their job earnings and taxes paid into the system over the years, on which future benefits are based.

At present, people receive a rather confusing response lumping most of their lifetime earnings into a single figure.

Under the alleged change, individuals at any time in their working lives could receive detailed information showing exactly how much they had earned each year since starting to work. In addition, if they submitted an estimate of what they expected to earn for the rest of their lives, they could receive a calculation of their future monthly benefits.

Well, work on the president's budget is almost complete, and -- subject to last-minute revisions -- none of these proposals is going to be in it.

For example, according to the list of decisions that the Office of Management and Budget has just sent to the Department of Health and Human Services, there is no plan to propose removing the NIH from HHS and "privatizing" it.

Instead, the OMB has simply told the department that NIH should commission a study by the Institute of Medicine "to look at the optimum organizational arrangement for its intramural program, including a privatization option." In other words, no immediate proposal, just a study of the inside research program, which probably won't be finished before Reagan leaves office.

Removal of the Social Security earnings limit is also not likely to be in the budget, although it is possible the administration will formally suggest the idea later, after further study.

Social Security Commissioner Dorcas R. Hardy proposed that the earnings limit be abolished for people age 65 and over, but not for those under 65. The OMB said the proposal was received too late for consideration as part of the fiscal 1989 budget. It also turned down Hardy's proposal for a revamped earnings-record-and-benefit estimate for people who write to ask their status under Social Security.

The OMB is proposing to cut Medicare, but only by cutting payments to hospitals or doctors, "not increases in beneficiary payments." According to HHS documents, it has ruled out a "Medicaid reform proposal" that cuts outlays.

One thing rumored, however, almost certainly will be in the budget. Everyone expected OMB to tell HHS to take another big personnel cut. The department in fiscal 1987 had 121,796 full-time employees, and OMB wants to cut it to 113,506 for 1989 and to 103,558 by 1993 -- largely by cutting Social Security's work force from 71,464 to 58,000 by 1993.